You're right, Dias De Verano, I asked the same question twice. I'm sorry. Mea culpa, mea culpa, mea culpa maxima. It is not logical, but I'm trying for something, anything, that might save this -- and it probably can't be saved. The file probably was overwritten. I don't mean to waste anyone's time.
So now we all get to explain to this poor person how to avoid this in the future, so I'm going to chime in with the standards that I know: A person wants to have at least two backup copies of important work, with (ideally) one of those copies being off-site. The USB flash drives, being inexpensive and portable, are extremely popular for this sort of thing. My warning would be, if the work or material is important enough, to utilize at least two flash drives. I had a flash drive fail last year. They are durable, and sturdy, for the most part, but they are not infallible.